ASC Engineered Solutions 21/2X11/2 GALV MI REDUCER

Both openings are female pipe thread (FPT), cut to ASME B1.20.1 NPT. So it takes male-threaded pipe nipples or male fitting ends on each side, 2-1/2 inch into the large end and 1-1/2 inch into the small end. Nothing is sweat, grooved, or press here.

The reducer is hot dip galvanized to ASTM A153, which is a heavier zinc coating than electroplating and is the usual choice for wet sprinkler systems, exposed piping, and damp mechanical rooms. The base casting is malleable iron to ASTM A197. Do not use it on potable water lines where a lead-free bronze or CPVC fitting is specified.

A reducing coupling has female threads on both ends and makes the size change inside its own body, so you thread pipe straight into each side. A bushing is male on the large side and female on the small side, and it has to sit inside an existing fitting. This ASC part is the coupling style, FPT on both ends, so use it where you are joining two pipe ends and want a full-bodied transition rather than filling a port on a tee or valve.

The strength class is STD, standard weight, which is the Class 150 malleable iron line in ASME B16.3. Pressure rating and face to face dimensions both follow B16.3 for that class. If the spec calls for 300 class extra heavy malleable iron, this is not the right fitting.

Manufacturer part number 311090203, ASC Engineered Solutions, galvanized malleable iron reducer, 2-1/2 inch by 1-1/2 inch FPT. Each piece weighs 2.11 lbs, which is what you want for hanger and support load takeoffs on a threaded run.

Mechanically yes, the threads are NPT to ASME B1.20.1 and will make up with black pipe. But mixing galvanized fittings onto black pipe is usually a spec violation on fire protection and mechanical jobs, and the galvanizing gives you no benefit if the pipe itself is bare. Match the fitting to the pipe system you are running.